The HKMA's latest round of measures intended to cool the property market by further restricting mortgage lending are unlikely to have much impact for the simple reason that so many properties are being purchased with cash and the impact of QE3 combined with China's monetary expansion means that there is plenty of very liquid buyers out there.
As with most of the previous measures, the two groups of people most affected as local owner-occupiers prevented from trading up because they can no longer get the financing and smaller investors who need mortgage financing to add to their portfolios. In effect, what the HKMA is doing (when combined with other government measures) is reducing the competition the very wealthy face when buying properties.
While it would now be more difficult to get mortgage financing for any new investment properties, since I was not planning to buy again at current price levels, this does not affect me. What it does do is reinforce my decision not to make any early repayments on my existing mortgages.